HELP - Fuel Screw Removal?

Folks, trying to add an aftermarket easy access Fuel Screw, but how in the heck do you get off the stock one? There's a small, almost flush component, just in front of the carb float bowl with a small hole in the middle of it. I thought it may be a small 1-2mm hex nut, but it doesn't appear to be a hex nut? I tried a 2mm hex tool and it's too big, a 1.5 mm is too small, so how do I get this thing out to insert the aftermarket screw?. Also, how in the heck would you even adjust it in stock form if no tool works with it?

p.s. I have an 06 WR 450. I also posted in the other forum, but no reply as of yet.


It should be a flat screw driver, the easiest way on older bikes to get it out was to loosen the carb and turn it. But on the 06's you need to either get a small screw driver and cut it off so you can get it out or take the carb off. You might be able to turn the carb enough on the 450's but i doubt it as my buddies 06 250f you couldn't do it.

I have a 2004 Yz 450f.....there is only a screw there on the Yz's, but I think I read that some of the WR models need to have a Tin "cup" or some other obstruction removed from the fuel screw housing to get to the fuel screw.

In other words, I think the California model's use an obstruction in front of the fuel screw, so that you don't monkey with the emissions. I think I remember hearing that people would use a sharp screw to turn into the "obstruction" and then yank out the "plug" than you have access to the fuel screw. Maybe other's will chime in about this.

OH, almost forgot......I think it is ILLEGAL to remove this obstruction according to the emissions laws of Cali. Because this bike could possibly be street legal, there are special rules regarding messing with the carb. Remember the Government doesn't care if your bike runs like crap (or uses more fuel than necessary) it's simply bureaucracy's.

I actually just put a MSR fuel screw in my '03 the other day and all I had to do was loosen up the front and rear boots on the carburator (only 1 of the boots connecting it to the motor) and I just had to twist it back and forth and side to side but finally it popped off the front. I moved it forward and to the left, and I was able to turn the carborator enough to get in there with a full size screw driver and replace the fuel screw. Make sure that when you do this, that you ground out the fuel screw so that you know how many turns out you had. You might want to invest in a official yamaha manual. They are way better than the cheap clymers.

Yeah, but he's asking about a WR model, not a YZ. YZ's are exempt from emisiions rules because they are Off-road vehicles. I'm assuming kawirider that you have a YZ (based on your listing of vehicles) and not a WR. I think the California WR model only is the one with the fuel screw blocked, but I'm not 100% sure.

You can remove the cap to access the screw. Either pry it out or drill it.

You are correct, there is a small round aluminum "obstruction" in front of the fuel screw which PREVENTS you from being able to get anything to the screw itself. It looks like it's part of the carb, so it's very misleading.

I pulled the carb out of the flanges and removed the float bowl altogether. Then I took a screwdriver and just gave the round piece a quick slap and the piece came out. Someone else mentioned to use a self-threading drywall screw. This would have worked equally as well.

Man, what a pain and the _SS!

BTW: I ended up stripping two of the cheap aluminum screws that attach the float bowl so they will need to be replaced. I'm just glad I was able to get the bowl off after stripped the screw heads. They are junk, be very, very careful when removing them.

Thanks again guys for your help on this. I was stumped, but it's been resolved.

Why California wouldn't allow you to make a simple fuel screw adjustment is retarded BTW. Do they think we all ride at the same altitude or what!

Peace out folks!


did the trick..thanks much!

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